A signed integer overflow in docopt.cpp v0.6.2 (LeafPattern::match in docopt_private.h) when merging occurrence counters (e.g., default LON…

published 2026-01-23 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-4308

cvss: 4.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits: 0; none known

A signed integer overflow in docopt.cpp v0.6.2 (LeafPattern::match in docopt_private.h) when merging occurrence counters (e.g., default LONG_MAX + first user "-v/--verbose") can cause counter wrap (negative/unbounded semantics) and lead to logic/policy bypass in applications that rely on occurrence-based limits, rate-gating, or safety toggles. In hardened builds (e.g., UBSan or -ftrapv), the overflow may also result in process abort (DoS).

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-67125 updated 2026-06-28 cvss 6.5

docopt.cpp: integer overflow can lead to logic/policy bypass

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 9 mo ago (2026-01-23)

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

gist.github.com https://gist.github.com/thesmartshadow/672afe8828844c833f46f8ebe2f5f3bd referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	4.4	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
CNA	3.1	4.4	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

Classification

Weakness

CWE-190 Integer Overflow or Wraparound

References

gist.github.com /thesmartshadow/672afe8828844c833f46f8ebe2f5f3bd
exploit, third-party-advisory
github.com /docopt/docopt.cpp
product

Sources

CVE List CVE-2025-67125
NVD CVE-2025-67125

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary